Traditional distributed motor windings use multiple turns of round wire (e.g., stranded magnet wire) and connections to achieve the desired connectivity. With these machines, the final windings and connections are typically formed by a press-die to produce the final shaped end-turns of the motor. As shown in FIG. 1, for example, a typical stranded wire stator slot configuration 100 within a stator core 109 includes a slot 102 that tapers slightly as it progresses from one end 106 (the end closest to the inner surface 110) to the opposite end 104, such that the stator teeth have parallel sides. The stranded wire (not illustrated) is then wound within slot 102.
In contrast, referring to FIG. 2, the use of hairpin or bar-wound configuration 200 in stators results in superior thermal performance as compared to stranded wire due to its larger end-turn surface area and much improved slot-fill. That is, a number of conductors 205 with generally rectangular cross-sections are inserted within slots 202 such that their sides are parallel, and the width of the slot 202 is relatively invariant as it extends from end 206 to end 204.
Although the latter geometry results in better slot-fill, the available area is limited due to the need for parallel slot faces to accommodate the conductors, as shown. This also results in an unsatisfactorily narrow intertooth distance d near the bottom conductors (adjacent inner surface 210), which can cause high saturation and lower machine torque.
Accordingly, it is desirable to provide improved bar-wound stator designs. Other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.